Sweet spot for Chaos Axe bonus % dmg pricing?

Well, naturally 15% dmg above 50% hp is most expensive from this bonus type but how prices drops when going to 14%, 13% and 12%? Asking because I'm looking for best price/stats-ratio.

Ignore upgrades or consider them to be almost cheapest around.

Don't know but I'd not buy it more than 6k. All those ebayers are f4cking the prices up with their "eternal bows / shields" etc. I saw a guy who wanted 120k for a max dmg Eternal Bow. So sad.

120k? Holy flaming arrows batman! For that price the damage should be 80-100.